issue_comments

I made it work with openpyxl. I'm not sure all the code under @hookimpl is necessary... but it works :)

```python from datasette import hookimpl from datasette.utils.asgi import Response from openpyxl import Workbook from openpyxl.writer.excel import save_virtual_workbook from openpyxl.cell import WriteOnlyCell from openpyxl.styles import Alignment, Font, PatternFill from tempfile import NamedTemporaryFile

def render_spreadsheet(rows): wb = Workbook(write_only=True) ws = wb.create_sheet() ws = wb.active ws.title = "decp"

columns = rows[0].keys()
headers = []
for col in columns :
    c = WriteOnlyCell(ws, col)
    c.fill = PatternFill("solid", fgColor="DDEFFF")
    headers.append(c)
ws.append(headers)

for row in rows:
    wsRow = []
    for col in columns:
        c = WriteOnlyCell(ws, row[col])
        if col == "objet" :
            c.alignment = Alignment(wrapText = True)
        wsRow.append(c)
    ws.append(wsRow)

with NamedTemporaryFile() as tmp:
    wb.save(tmp.name)
    tmp.seek(0)
    return Response(
        tmp.read(),
        headers={
            'Content-Disposition': 'attachment; filename=decp.xlsx',
            'Content-type': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
        }
    )

@hookimpl def register_output_renderer(): return {"extension": "xlsx", "render": render_spreadsheet, "can_render": lambda: False}

```

The key part was to find the right function to wrap the spreadsheet object wb. NamedTemporaryFile() did it!

I'll update this issue when the plugin is packaged and ready for broader use.

Apparently, beside a string, Reponse could also work with bytes.